Update launcher.sh

replaced $DOCKER_HOST with $RABBITMQ_HOST variable, since Docker -H definition requires a port
with a Docker also reading the $DOCKER_HOST variable it would confuse Docker to find the right instance without a port
Update README.md

Replace DOCKER_HOST with RABBITMQ_HOST variable
Merge pull request #9 from chauthai/master

Replacing DOCKER_HOST varibale with RABBITMQ_HOST